Description: Equivalence of function value and ordered pair membership, analogous to fnopfvb . (Contributed by AV, 6-Sep-2022)
Ref | Expression | ||
---|---|---|---|
Assertion | fnopafv2b | ⊢ ( ( 𝐹 Fn 𝐴 ∧ 𝐵 ∈ 𝐴 ) → ( ( 𝐹 '''' 𝐵 ) = 𝐶 ↔ 〈 𝐵 , 𝐶 〉 ∈ 𝐹 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fnbrafv2b | ⊢ ( ( 𝐹 Fn 𝐴 ∧ 𝐵 ∈ 𝐴 ) → ( ( 𝐹 '''' 𝐵 ) = 𝐶 ↔ 𝐵 𝐹 𝐶 ) ) | |
2 | df-br | ⊢ ( 𝐵 𝐹 𝐶 ↔ 〈 𝐵 , 𝐶 〉 ∈ 𝐹 ) | |
3 | 1 2 | bitrdi | ⊢ ( ( 𝐹 Fn 𝐴 ∧ 𝐵 ∈ 𝐴 ) → ( ( 𝐹 '''' 𝐵 ) = 𝐶 ↔ 〈 𝐵 , 𝐶 〉 ∈ 𝐹 ) ) |